Removed some warnings (some, there is a lot more)
LookAndFeel fixes:
- components that change the look and feel of their children (slider, combo)
  need to reset the LookAndFeel of those children when a new LookAndFeel is set
  for them, otherwise it won't affect their children (they will use the object
  passed explicitly)

- need to pass special wrapper objects where there are references to primitive types
  in method calls (int &), this is not allowed in luabind